In the field of medicine, imaging and image guidance are a significant component of clinical care. From diagnosis and monitoring of disease, to planning of the surgical approach, to guidance during procedures and follow-up after the procedure is complete, imaging and image guidance provides effective and multifaceted treatment approaches, for a variety of procedures, including surgery and radiation therapy. Targeted stem cell delivery, adaptive chemotherapy regimes, and radiation therapy are only a few examples of procedures utilizing imaging guidance in the medical field.
Advanced imaging modalities such as Magnetic Resonance Imaging (“MRI”) have led to improved rates and accuracy of detection, diagnosis and staging in several fields of medicine including neurology, where imaging of diseases such as brain cancer, stroke, Intra-Cerebral Hemorrhage (“ICH”), and neurodegenerative diseases, such as Parkinson's and Alzheimer's, are performed. As an imaging modality, MRI enables three-dimensional visualization of tissue with high contrast in soft tissue without the use of ionizing radiation. This modality is often used in conjunction with other modalities such as Ultrasound (“US”), Positron Emission Tomography (“PET”) and Computed X-ray Tomography (“CT”), by examining the same tissue using the different physical principals available with each modality. CT is often used to visualize boney structures, and blood vessels when used in conjunction with an intra-venous agent such as an iodinated contrast agent. Vascular visualization may also be acquired by MRI using a contrast agent, such as an intra-venous gadolinium based contrast agent which has pharmaco-kinetic properties that enable visualization of tumors (in some instances), and break-down of the blood brain barrier. These multi-modality solutions may provide varying degrees of contrast between different tissue types, tissue function, and disease states. Imaging modalities may be used in isolation, or in combination to better differentiate and diagnose disease.
Patient positioning is often the most time-consuming aspect of setting up for an imaging study, including MRI studies. For example, it is desirable to align the patient anatomy as much as possible to the imaging device (e.g. scanner) frame of reference. This is analogous to the way a map is aligned to a compass when way finding in the physical world. However, due to patient comfort and other factors, such as the way external equipment is attached, and/or how a patient is anchored to a scanning bed, alignment of patient anatomy to the imaging device frame of reference is not always possible. In particular, a patient is positioned in their most comfortable position to minimize patient movement during a scan. Even when in an interpretative situation, where a patient may be sedated, optimal positioning may be limited because of a site of a surgery and the way patient was optimized for the surgical position.
As a result, it is often necessary to provide instructions to the imaging device/scanner on a desirable scan orientation based on the way patient is positioned. This way, the imaging device/scanner may adjust its magnetic gradient (e.g. for an MRI) accordingly during image acquisition and provide an output of the anatomy that is oriented in a clinically relevant way. For example, instead of a typical supine or prone position, the patient maybe positioned in a lateral recumbent position with their head rotated in a way that is optimized for a surgical access to the lateral side of their head. If the patient is scanned without adjustment to the scan orientation, the scanner will make assumption about the right, left, anterior, posterior, superior, inferior direction and output misleading directional information on the resulting image. In the less severe case where the patient is aligned closely to the scanner frame of reference, clinicians would still like to conveniently make adjustment to the scan orientation so that the internal anatomy appears as similar to textbook anatomy as is possible.